Just keep a close eye on kitty, i am sure it is nothing to worry about, just normal, either a kitty hairball or just a vomit, i have a
cat that vomits all the time,(The big grey boy in my siggy, now he does not look unhealthy does he? and according to the vet is in good condition) nearly everyday, and the vet is not concerned, some cats are just like that i was told, of course we outruled other problems first that could be associated with vomiting, kitty could have an allergy problem to the food your are feeding it, that is also something you could look into, according to the producers of Felidae a very good natural cat food, anything with soy, corn or wheat grains are often causes of allergys for cats, they are often found in the cheaper brands of food.